While you are looking, take this advise based on my mistake. I just switched from standard Midwest Industry rear buis to the Troy Battlesight for two reasons.
One, the elevation knob on the Midwest Industries sight got in the way of the charging handle making it awkward to grasp. A lot of these sights have knobs that overlaps the right side of the charging handle when they are installed in the proper, rearmost position. The Troys, like the Magpuls don't have the pronounced knob and therefore do not interfere with the operation of the charging handle. They just fit in between the T.
Secondly, the Troys are low profile and more likely to fit under a scope or magnifier. I think they are under .5 inches vs the MI sights at .75 inches. They are more versatile. Again, MBUS is low profile.
Lots of people use the Magpuls and I have yet to hear complaints about them breaking.